High-level diplomats from the United States and Japan have arrived in South Korea to fine tune strategy ahead of Wednesday's six-nation talks in Beijing on dismantling North Korea's nuclear weapons program.

With just days to go before the high-stakes talks, American, Japanese and South Korean diplomats are huddling in Seoul.

Director General Mitoji Yabunaka of the Japanese Foreign Ministry's Asian Affairs Bureau and U.S. Assistant Secretary of State James Kelly arrived in the South Korean capital on Sunday to meet with South Korea's Deputy Foreign Minister Lee Soo-Hyuck.

The United States, Japan and South Korea will join North Korea, China and Russia at the table in Beijing beginning Wednesday. Although Beijing has expressed optimism about a breakthrough, some of the other participants say they have few expectations because of the lack of trust between Washington and Pyongyang.

Washington and its two Northeast Asia allies say they want the second round of the multilateral talks to cover both North Korea's plutonium and uranium nuclear weapons programs. The three nations say that North Korea must agree to permanently dismantle all nuclear programs and allow verification of that.

South Korea's Foreign Minister Ban Ki-moon on Sunday said Pyongyang must meet this condition before Seoul will send any additional aid to the North.

Japan's foreign minister, on Sunday, expressed doubt the communist state will open its nuclear facilities to international inspection. Yoriko Kawaguchi, appearing on a television interview program, added she hoped that talks would not break down on the first day.

North Korea last month proposed freezing its plutonium-based program in exchange for energy aid and diplomatic rewards. It has denied having a program to enrich uranium.

Tensions escalated in October 2002 when the United States said North Korea had admitted having a secret uranium-based weapons program in violation of international agreements.

On Saturday, an official dispatch from North Korea's news agency said a top Pakistani scientist uttered a "whopping lie" in saying he sold nuclear secrets to Pyongyang. Mr. Abdul Qadeer Khan has also admitted passing nuclear technology and know-how to Iran and Libya.

Many analysts say they expect that this latest round of talks about the North Korean nuclear crisis will be one of many in a series that will take time to achieve any significant breakthroughs.